What is/how to lolipop(ing)

I read in a thread about lolipopping to give plants more light in the lower parts

how is this done/what is it?

i think you read the wrong thread.

you remove the lower third of the plant (in veg) that will not receive enough light, causing popcorn buds in flower. this will also help the plant revert the energy to produce bigger buds. this technique works well in a SOG.

if confirmed females, use the lower branches that were removed for clones..